This invention relates to the spring for biasing closed the access door on a videocassette of the type used in a video recording and playback machine, such as the "U-Matic" cassette developed by Sony Corporation.
As is best seen in FIG. 2 of U.S. Pat. No. 3,809,219, a prior art video tape cassette or videocassette 10 typically comprises a length 19 of magnetizable recording tape, two reels 17 and 18 each supporting a different helically wound end portion of the length 19 of tape, and a generally rectangular housing 11 enclosing and supporting the reels 17 and 18 for rotation to transfer tape between the reels 17 and 18. The housing 11 includes an outer front wall having generally planar end portions and a recessed portion 16 defining a tape access area along the outer surface of the housing 11, and guide pins 20 and 21 for guiding tape between the reels 17 and 18 through the outer wall and across the recessed portion 16 to afford access thereto by the mechanism 62 of a video tape recording/playback machine. A door 22 is pivotably mounted on the housing via a hinge assembly for movement between a closed position over the length of tape 19a extending through the tape access area (FIG. 5 of U.S. Pat. No. 3,809,219) and an open position (FIG. 1) spaced from the tape access area, with the door 22 being biased to its closed position by a coil spring 25 tensioned between the housing 11 and the door 22.
While the use of such a coil spring is effective in biasing the door to its closed position, it is difficult to assemble into the cassette and thus adds to the cost of the cassette.